With the use of the exact theory of nonlinear elasticity, [1]} derived the following asymptotic expansion for the critical strain when a neo-Hookean film bonded to a much softer neo-Hookean substrate is subjected to a uni-axial compression:
\(1-\lambda = \frac{r}{2 k h}+\frac{1}{12} (k h)^2-\frac{13}{480} (k h)^4-\frac{3}{8} \cdot \frac{ r^2}{ (kh)^2}+O((kh)^5),  \) 
